from langchain_core.output_parsers import StrOutputParser
from langchain_core.prompts import ChatPromptTemplate
from langchain_openai import ChatOpenAI

llm = ChatOpenAI(
    api_key="sk-a3f7718fb81f43b2915f0a6483b6661b",
    base_url="https://dashscope.aliyuncs.com/compatible-mode/v1",
    model="llama-4-scout-17b-16e-instruct",  # 此处以qwen-plus为例，您可按需更换模型名称。模型列表：https://help.aliyun.com/zh/model-studio/getting-started/models
    # other params...
)
prompt = ChatPromptTemplate.from_template("请讲一个关于{topic}的笑话")
output = StrOutputParser()
chain = prompt | llm | output
print(chain.invoke({"topic":"猫"}))